After Isil claimed the attacker was a "soldier" of the terror group, Scotland Yard formally identified the 52-year-old - saying he was not the subject of any current investigations and there was "no prior intelligence about his intent to mount a terrorist attack".

But the man who killed four people - including a police officer - in the shadow of the Houses of Parliament had a range of previous convictions for assaults, including GBH, possession of offensive weapons and public order offences. He had not been convicted of any terrorism offences.

It comes as police said a fourth innocent victim died on Thursday night. The 75-year-old man died from his injuries in hospital.

A Scotland Yard spokesman said: "The man had been receiving medical treatment in hospital following the attack and life support was withdrawn this evening.

"Next of kin have been informed and are receiving support from specially trained family liaison officers."

Khalid Masood being treated by medics after he was shot outside the Palace of WestminsterCredit: Stefan Rousseau/PA

But by the time Masood went on the rampage on Wednesday, driving a car at 50 miles an hour along Westminster bridge, murdering three innocent pedestrians before plunging his knife repeatedly into a police officer guarding the Houses of Parliament, he had dropped off their radar.

Masood, a father of three, was no longer considered a threat. The Telegraph can disclose that Masood was not using his birth name. He was born Adrian Elms in Dartford, Kent.

Just two hours after Theresa May told the Commons the killer was a British citizen who had been investigated by MI5 over violent extremism, Isil said that the attacker answered "calls to target citizens of coalition nations". Isil had vowed that the UK was its next target following the Paris attacks in 2015.

Isil statement released by Amaq news agency on Thursday afternoon

The Prime Minister earlier said the attacker was known to the police and security services, as she defiantly vowed: "We are not afraid and our resolve will never waiver in the face of terrorism."

It comes as Scotland Yard disclosed that the eight people - three women and five men - arrested in London and Birmingham are being held on suspicion of preparation of terrorist acts.

Detectives are continuing to search a number of addresses linked to the investigation: one in Carmarthenshire, three in Birmingham; and one in east London.

A total of 29 people were treated in hospital following the carnage, with five people remaining in a critical condition on Thursday evening - two of them with life-threatening injuries.

Among the injured were 12 Britons, including three police officers who were returning from an event to recognise their bravery.

Meanwhile, at the scene of one of the police raids - a flat in Hagley Road, Birmingham, where the attacker is believed to have lived - witnesses told how black-clad officers equipped with machine guns smashed their way into the property.

One neighbour told The Telegraph: "It's left me so scared and I don't know what to tell the children. He seemed like a normal calm and kind family man, always with a smile on his face."

The attacker mowed down pedestrians with a car on Westminster Bridge before crashing at the railings in front of Parliament.

Masood 'spent time in Saudi Arabia'

The Sun has reported that Masood visited Saudi Arabia in 2005. According to a CV that the newspaper claims it obtained, he was working in Yanbu, Saudi Arabia, then teaching workers at the General Authority of Civil Aviation (GACA) in Jeddah.

If confirmed, it would raise questions as to whether he was radicalised before or during his time abroad. The Telegraph has reported he is understood to have gone to jail in the past, where there is a good chance he was radicalised. It is at that stage, it is thought, he came onto MI5’s radar.

'All day, I couldn't get it out of my head'

A British boxing team have recalled the horror of witnessing Pc Keith Palmer being stabbed as they secured victories in the ring a day after the attack.

Coach Tony Davis was outside the Houses of Parliament after attending a community event with the British Lionhearts team when terror unfolded in front of him.

Tony Davis, who was first on the scene of the Westminster attack, speaks on ITV's This Morning programmeCredit: ITV

The four fighters at his side spoke of their trauma after seeing the hopeless efforts to revive the officer.

Flyweight and 2016 Olympian Muhammad Ali, who won his fight by unanimous decision on Thursday night, said: "All day, I couldn't get it out of my head because we saw everything."

Fellow member of the British Lionhearts, welterweight Pat McCormack, added: "I didn't really sleep much. My head was a bit all over and I couldn't really stop thinking about it but I'm just glad I've come, got the job done and the win."

Davis told Press Association Sport:

"We had just attended a PR event at the Houses of Parliament and as we were leaving we could just see straight in front of us, on the outside of the perimeter fence, a bit of a fracas.

"It was loud volume, but I didn't think much of it. I thought it must be a student demonstration but then the mood changed as I saw someone come through the gate with knives above his head and start attacking the police officers.

"When I saw that I jumped over what was maybe a 4ft fence to try to give assistance but a lot of things happened in a few seconds.

"As the assailant was advancing he got taken out by one of the police marksmen. Then I just tended to Keith Palmer, who was collapsing on the floor."

Masood reportedly said 'London isn’t what it used to be' on morning of attack.

Khalid Masood was born Adrian Elms in Dartford, Kent

Robert Mendick writes:

As long as a decade ago, Khalid Masood’s “violent extremism” had caused security services sufficient alarm to put him under investigation.

But by the time Masood, 52, went on the rampage on Wednesday, driving a car at 50 miles an hour along Westminster bridge, murdering three innocent pedestrians before plunging his knife repeatedly into a police officer guarding the Houses of Parliament, he had dropped off their radar.

Masood, a father of three, was no longer considered a threat. The Telegraph can disclose that Masood was not using his birth name. He was born Adrian Elms in Dartford, Kent.

Urging calm within all communities and offering condolences to those bereaved by the attack, Mr Afzal added: "The Islamic faith does not allow anyone to take the life of others.

"No religion justifies the indiscriminate killing of individuals in such a barbaric and heartless way, and such acts only serve to differentiate between the misguided and the just.

"We call upon those that may have even a shred of sympathy for the like-minded terrorists to shake their conscience and realise that such acts are the work of evil and not the work of God-fearing people."

In a statement on Facebook, the organisers of the vigil wrote: "Our thoughts are with all those affected by what has happened.

"Birmingham is a united city and we will not let anyone use these terrible events to divide us. Please come and join us on Friday for a unity vigil."

'Teacher' Masood had never worked in English state schools

Controlled explosion near Downing Street

A controlled explosion on a suspicious package is believed to have taken place near Downing Street tonight.

The BBC News Channel reported that a loud bang had been heard within earshot of their live broadcast. Officers said it had taken place on Birdcage Walk, not far from the Houses of Parliament and Downing Street.

Minute's silence held around the world for London attack victims

In pictures and video: tonight's vigil at Trafalgar Square

After Wednesday's events, there was a determination throughout the city to carry on in the face of it all. The mood at Trafalgar Square was sombre but defiant, as people of all ages and backgrounds stood together, many of them Muslims holding up signs saying: "Love for all, hatred for none".

Credit: Jack Taylor /Getty

Among those who came to pay their respects was Jess Okpere, whose teacher Aysha Frade lost her life on Westminster bridge.

Carrying a bunch of daffodils and clearly very emotional, the 18-year-old said: "I cried this morning when I found out. I've had a very long day filled with a lot of tears. I'm here to show that we're not going to let these people win."

Credit: YUI MOK /PA

Standing on the steps in front of the National Portrait Gallery, faith leaders joined Home Secretary Amber Rudd, Acting Met Commissioner Craig Mackey and Mayor of London Sadiq Khan. Three large candles in glass hurricane lanterns sat before them.

The respectful hush in the square was broken only by applause, as the Home Secretary praised PC Keith Palmer.

Credit: Eddie Mulholland for the TElegraph

"He was courageous, he was brave and he was also doing his duty," she said. "It reminded us of how we are all connected."

In an impassioned address, Ms Rudd said: "The terrorists will not defeat us, we will defeat them."

Sadiq Khan spoke of how Londoners had come together in the aftermath of the attack.

He said: "London is a great city full of amazing people from all backgrounds, and when Londoners face adversity, we always pull together.

"Our response to this attack on our city, on our way of life, our shared values, shows the world what it means to be a Londoner."

The crowd fell quiet as a minute's silence was observed in honour of the victims. Many bowed their heads, while others clung to each other for comfort.

Credit: REUTERS/HANNAH MCKAY

As the silence lifted, people began lighting candles and placing them in boxes filled with sand. Soon, the faces of people all over the square were lit with candlelight.

Amanda Goodhugh, who works at St Thomas's Hospital, where two of the victims were taken on Wednesday, sat on the edge of one of the fountains and cried, her face in her hands.

Credit: Eddie Mulholland for The Telegraph

She told the Telegraph she had been overcome with emotion watching people come together in solidarity. "People's positive response is what is making me so emotional," she said.

"That, and the staff at my hospital who ran out into the road yesterday to help. That is what healthcare in this country is all about."

The Daily Telegraph understands that police have raised repeated concerns about the security of the gate, which has been described as a “weak point”.

In February the House of Commons administration comittee discussed the issue, with a particular focus on the “flimsy” and “Meccano” crowd-control barriers in front of the wrought-iron gates.

The barriers have to be manually opened by police on the pavement outside Parliament, which MPs said put them at risk. The MPs called for them to be replaced with a stronger, automated gate which police could operate remotely.

Bursts of applause were the only sounds which interrupted the speeches there tonight.

Candles were lit and a mintue's silence was observed for the three innocent victims who died in the attack.

Meanwhile prayers were said in Parliament for Pc Keith Palmer just metres from the spot where he was stabbed to death.

Rev Rose Hudson-Wilkin, the chaplain to Commons Speaker John Bercow, condemned the "act of evil" but urged people to remember the "acts of goodness" demonstrated by people who tried to help those killed and injured in the attack.

Pc Keith Palmer lost his lifeCredit: LONDON METROPOLITAN POLICE

In a moving service in the Chapel of Saint Mary Undercroft within the Palace of Westminster, the chaplain warned against the danger of thinking "an eye for an eye" and urged people to share memories of the "heroic contributions on that day when evil dared to show its face".

The ornate chapel, just off Westminster Hall, is a short distance away from New Palace Yard where Pc Palmer lost his life.

Jeremy Corbyn: We need to stand together against hatred

Armed police should be at 'sensitive sites'

Police should consider arming all officers guarding "sensitive sites" after the London terror attacks, according to a Tory MP, our deputy political editor Steven Swinford reports.

Theresa Villiers, the former Northern Ireland secretary, suggested the issue of whether police who patrol areas "known to be of interest to terrorists" should carry a weapon for personal protection should now be examined.

Theresa May said who carries arms remains an "operational matter" for the police.

Ms Villiers said: "As we reflect on what happened, is it time to consider whether the police who guard sensitive sites known to be of interest to terrorists like Parliament or like airports should routinely carry personal protection weapons, even when those officers are not part of the units formally tasked with armed response?"

"The terrorist attack in Westminster on Wednesday was horrific and our thoughts are with all of those affected by it.

"The IPCC is responsible for investigations into fatal police shootings. Accordingly, after being notified by the Metropolitan Police Service of the fatal shooting of a man outside the Houses of Parliament, we have opened an independent investigation. It's important to stress that we are currently investigating the circumstances of the incident and no police officers are under investigation.

"The IPCC and the Metropolitan Police Service are following agreed working arrangements related to terrorist incidents, which are working well. I recognise that this is a very difficult time for the police service, following the tragic loss of Pc Keith Palmer and the injuries to other officers. We are giving this investigation the highest priority and we will conclude it as soon as possible."

Pupil of terror victim: I'm here to show that we're not going to let these people win

A pupil of Westminster victim Aysha Frade, a Spanish teacher, who lost her life in the attack, has come to pay her respects in Trafalgar Square.

Carrying a bunch of daffodils, 18-year-old Jess Okpere told The Telegraph's Eleanor Steafel: "I cried this morning when I found out. My school paid tribute to her. There were so many people crying, people who saw her every day.

"I was in the McDonalds by the London Eye in my free period when it happened. I didn't see it happen but I saw the aftermath, the ambulances and the stretchers.

"I've had a very long day filled with a lot of tears. I'm here to show that we're not going to let these people win."

'I am a Muslim, ask me anything' - T-shirts in Trafalgar Square

As a crowd gathers at Trafalgar Square, a handful of people are wearing t shirts with the words: "I am a Muslim, ask me anything" printed on them. Three members of the group are holding up a banner which reads: "Love for all, hatred for none".

A crowd is beginning to gather at Trafalgar Square, where from 6pm Londoners will hold a vigil in honour of the four innocent people who lost their lives, Eleanor Steafel reports.

Speaking ahead of the vigil, London Mayor Sadiq Khan said this morning: "Tonight in Trafalgar Square there will be a vigil for Londoners who are wondering what to do.

"To show solidarity with those who have lost their lives and their families, to show solidarity with those who have been injured, and to say to the terrorists: 'You will not succeed in cowering us, we will remain united, and we are the greatest city in the world'."

Michael Deacon's Commons sketch: Tributes, tears – and then steely resolve: how Parliament got back to business

They carried on. A wide area around the Palace of Westminster had been cordoned off, the Tube station was shut, and most entrances to the estate were closed. Yet this morning, refusing to be cowed, Parliament went back to work.

Masood neighbour: 'It's left me so scared... he seemed like a normal calm and kind family man'

Patrick Sawer reports from Birmingham:

A mother of three was left stunned after recognising Khalid Masood, the terrorist pictured on a stretcher after Wednesday's attack, as the man who had lived next to her for several months.

Iwona Romek said she had been left terrified by the realisation she might have been living next to a fanatical terrorist who she had previously regarded as a "calm family man". She told The Telegraph:

"I'm so scared for my children knowing that he lived so near to us. We've lived here for 12 months and I never could have imagined that we were living next to someone who would do something so terrible.

"It's left me so scared and I don't know what to tell the children."

Mrs Romek, a cake factory worker from Poland who has lived in Birmingham since 2005, said the man - who she said looked in his late 40s - had lived at No. 4 Quayside, in the Winston Green district, for around seven months, before leaving suddenly about two months ago.

He lived with a woman of Asian appearance in her 30s who covered her hair with the hijab when outdoors, and their five year old child.

"I used to see them taking the child to school in their car. The man would smile but we never spoke," said Mrs Romek, whose children are aged 25, 15 and eight. "He seemed like a normal calm and kind family man, always with a smile on his face."

She also spoke to medical staff to thank them for their work, said her official spokesman, who declined to name the hospital where the private visit took place.

Many of those injured on Westminster Bridge were taken to St Thomas' Hospital, which faces the Palace of Westminster across the Thames. Others went to King's College Hospital and the Royal London Hospital.

Mrs May also signed a book of condolence for victims of the attack in the House of Commons.

Pc Keith Palmer's family: He was proud to be a police officer, brave and courageous

The family of Pc Keith Palmer, the officer killed in the Westminster attack, have described him as a "wonderful dad and husband, a loving son, brother and uncle", adding that he was "dedicated to his job and proud to be a police officer, brave and courageous". They said:

"Keith will be remembered as a wonderful dad and husband. A loving son, brother and uncle. A long-time supporter of Charlton FC.

"Dedicated to his job and proud to be a police officer, brave and courageous. A friend to everyone who knew him.

"He will be deeply missed. We love him so much. His friends and family are shocked and devastated by his loss and ask that they are left to grieve alone in peace."

A spokesman for the Italian embassy said: "The ambassador was visiting for almost an hour visiting one of the victims, who is Italian. He brought flowers and gave her comfort.

"She was one of the people hit by the car. She is not in any serious danger of her life. She was just walking when it happened and had to undergo minor surgery to her left leg. She is expected to be released in the next few days."

Boris Johnson lays into social media over radicalisation

"If we are going to defeat these guys we are going to have to engage not just miltarily but also to win in their hearts and minds and stop the stuff on the internet that is corrupting and polluting so many people.

"This is something the internet companies and the social media companies need to think about. They need to do more to take that stuff off their media.

"The incitements, information about how to become a terrorists, the radicalising sermons and messages, that needs to come down ."

Boris Johnson addressing the United Nations Security Council in New York on Thursday afternoonCredit: Richard Drew/AP

Police create Westminster attack condolences website

Silence held in Spanish region where British victim's family originates

At least 100 people have attended a memorial in Spain to commemorate Aysha Frade, who was also killed in the terror attack.

A minute's silence was held in the Galician municipality of Betanzos, where the British woman's family originates and where she spent her summers.

Betanzos councillor Andres Hermida said the community in Spain was in "enormous pain" and shrouded in an "atmosphere of sadness".

An employee sets the Spanish flag at half mast on a balcony of the council of BetanzosCredit: MIGUEL RIOPA/AFP

He said: "We had a minute's silence in the Plaza de la Constitucion outside the local government building and we have declared three days of mourning, which will include flying the flag at half mast until Saturday.

'I wouldn't recognise them if I saw them', says landlord of Birmingham flat where three men arrested

Patrick Sawer reports from Birmingham:

Farhad Makanvand, the owner of the flat above a Persian restaurant raided by police in Birmingham on Wednesday night, told The Telegraph: "I own the restaurant and the two flats. Three men were arrested from my seven-bedroom flat.

"I don't know who the men were because I let it out via an agency. I wasn't in the restaurant at the time of the raid, I found out about it from neighbours.

"I voluntarily gave a statement to police this morning. But if I saw the three men who live there I wouldn't recognise them."

Farhad Makanvand, landlord of the Birmingham property raided by counter-terror police late on WednesdayCredit: Michael Scott/Caters

Mr Makanvand said he had been left "deeply shocked" by the sequence of events which culminated in the raid on his premises on Birmingham's Hagley Road.

He said he was cooperating fully with the police to help them with their investigations into the attack on Parliament.

Terrorist was shot dead by Sir Michael Fallon's bodyguard

A Cabinet minister's bodyguard was the officer to stop the Westminster terrorist, it has emerged, raising fresh questions about Parliament's security arrangements, reports Gordon Rayner and Kate McCann.

The close protection officer - understood to be the bodyguard of Defence Secretary Sir Michael Fallon - ran towards the knife-wielding attacker and shot him three times in the chest from short range. Read more here.Te

French foreign minister flies to London to visit pupils hurt in attack

France has opened an inquiry into "flagrant attempted murder" after three high school students were injured in the Westmisnter attack, reports Henry Samuel. It is being handled by domestic security, DGSI, and the French anti-terror body SDAT.

Meanwhile, Jean-Marc Ayrault, the French foreign minister, has flown directly to London from Washington to show support and to pay a visit to the French pupils caught up in the drama.

"I was adamant to make a stop in London to convey a message of solidarity to the British people," he said. "We will not forget the solidarity the British people demonstrated when we suffered (terror attacks)."

"When we heard the news of the attack, we immediately felt a shock, particularly because young French pupils were involved. We must continue to fight. It is a symbol of democracy that came under attack."

The French students were among those injured in the Westminster Bridge massacreCredit: TOBY MELVILLE/Reuters

Some 56 pupils from Saint-Joseph lycée in Cocarneau, Brittany were due to be debriefed by police at the hotel Marriott Westminster before flying home in two French military planes.

"We organised their repatriation by plane. It will take place today," said Juliette Meadel, French secretary of state in charge of aid to victims.

Paul Nuttall: Muslim communities have to do more to root out 'this cancer of radicalisation'

Speaking near Parliament, Ukip leader Paul Nuttall said the country must ensure there was no "knee-jerk" reaction after the "evil" attack and called on people to "come together and ensure that we move on forward".

He said he was "horrified" by the "act of insanity", but said that Muslim communities had to "do more to root out this cancer of radicalisation".

Mr Nuttall said that "we have to do something about people who will be returning from Syria", who he said should not be allowed back into the UK.

However, he added: "Let's be frank about this, only a tiny fragment of the Muslim community in this country are radicalised - probably one per cent - so the majority should not be blamed for the actions of one lunatic.

"But what will become clear I'm sure is that this is a lone wolf attack, but lone wolf attacks aren't always just committed by one person on their own. There'll be other people who would have known about this... and I just wonder whether more could have been done to stop them."

Duchess of Cambridge sends 'thoughts and prayers'

The Duchess of Cambridge, speaking at an event in London, has sent her "thoughts and prayers" to all those "sadly affected by yesterday's terrible attack in Westminster", reports Hannah Furness.

Speaking at the launch of Best Beginnings, a charity project for mental health in parenthood, she said: "Before I begin, I know you would all want to join me in sending our thoughts and prayers to all those sadly affected by yesterday’s terrible attack in Westminster.

"We will be thinking of all the families, as we discuss the important issues we're here to talk about."

The Duchess of Cambridge pictured on Thursday morningCredit: Chris Jackson/Getty

Scottish independence referendum debate put on hold

First Minister Nicola Sturgeon has said Scotland stands in solidarity with London following the "heinous" terrorist attack on Westminster.

In a bid to reassure people, she said there had been a "substantial uplift in armed officers on duty" across Scotland's major cities.

The First Minister, though, also urged the public to go about their business "confidently and defiantly".

Flags were at half-mast at Holyrood as Ms Sturgeon updated MSPs on the situation.

The attack took place while MSPs were debating Ms Sturgeon's plans for a second Scottish independence referendum to be held in the wake of Brexit.

The debate has now been put on hold until Tuesday March 28, when Holyrood is likely to vote to give the First Minister the authority to seek talks with Westminster over a section 30 agreement, the mechanism to transfer the powers for a legally-binding ballot to take place

Statement from Islamic State, which singled out UK as next target

The statement reads: "The attacker is a ISIS soldier who answered the call to attack countries participating in the anti-ISIS coalition."

Josie Ensor, the Telegraph's Middle East Correspondent, reports the group's late spokesman, Abu Mohammed Adnani's, previously called on followers abroad: "If you are not able to find an IED or a bullet, then single out the disbelieving American, Frenchman, or any of their allies.

"Smash his head with a rock, or slaughter him with a knife, or run him over with your car.”

Isil has been explicitly threatening attacks on Britain for the last 18 months. At the end of a propaganda video claiming the Paris attacks in November 2015, Isil singled out the UK as its next target.

Security stepped up in Rome as EU leaders prepare to descend on city

Security is being stepped up in Rome in light of the London terrorist attack as EU leaders prepare to descend on the city for the 60th anniversary of the Treaty of Rome on Saturday, reports Nick Squires in Rome.

More than 3,000 police are being deployed to the streets of the capital. Authorities are already deeply concerned about the six demonstrations planned on Saturday, but they are now worried about the risk of a terrorist attack too.

Security measures have been stepped up around the Italian parliament, the president's palace on the Quirinale Hill as well as at well-known monuments such as the Colosseum. Police and the Carabinieri are deploying armoured vehicles equipped with water cannon.

It comes as it emerged an Italian woman is among the injured from the attack. She is believed to be from Rome.

A second Italian, a woman from Bologna, is also reported to have been lightly injured when the terrorist rammed his car into crowds on Westminster Bridge.

"When the attack happened, my niece was walking across the bridge and was then crushed against the railings," the woman's aunt told Italian television.

"She seems to have been shielded from the worst of it by the group of French children who were hit. It is just awful, it's so shocking what happened."

Boris Johnson: 'The worst way to lose the war on terror is to be terrified, and we are not terrified'

Boris Johnson, in New York to attend the UN later today, has been speaking on the Morning Joe breakfast show, reports Harriet Alexander.

He was asked about the row about Sadiq Khan's September 2016 remarks that living with the threat of terrorism was a part of life in a big city - something which Donald Trump's son Don Jr misquoted, tweeting yesterday: "You have to be kidding me?" The Foreign Secretary said:

"There are always a certain number – for all the time I was mayor, we had people we were monitoring and watching.

"The crucial message, I think, was the one the Prime Minister gave this morning. It’s a city getting on with its business – parliament is running, transport is working.

"The worst way to lose the war on terror is to be terrified, and we are not terrified."

Video: Defiant London commuters vow to carry on regardless

Video: MP breaks down as he pays tribute to his friend Pc Keith Palmer

A Conservative MP was on the edge of tears as he paid tribute to Pc Keith Palmer who he met as “Gunner Palmer” when they served in the Army 25 years ago.

James Cleverly said Pc Palmer was "a strong, professional public servant and it was a delight to meet him here again only a few months after being elected”.

Mr Cleverly, his voice cracking with emotion, asked if Theresa May would recognise the work that he did and other police officers “consider recognising his gallantry and sacrifice formally with a posthumous recognition”.

Mrs May replied Pc Palmer had paid the “ultimate sacrifice” by giving his life in “the heart of democracy”.

The Prime Minister added she can assure Mr Cleverly that “the issue that he has raised is of course one that will be considered in due course”.

Woman who plunged into Thames as terrorist struck was on holiday with her fiance

Police rescued Andreea Cristea, a 29-year-old architect, from the river following the attack, and she is now in a serious condition in hospital.

Her partner, engineer Andrei Burnaz, was also taken to hospital with a fractured foot.

Andreea Cristea fell into the River ThamesCredit: Facebook

The couple had been walking across the bridge towards the London Eye when the terrorist ploughed a 4x4 car through pedestrians, before getting out and stabbing Pc Keith Palmer to death at the entrance to Parliament.

Paul Ciocoiu, a spokesman for the Ministry of Foreign Affairs in Romania, said he believed MIss Cristea had been “hit by a car and then thrown into the Thames”.

The pair were on their way to meet a friend, Patrick Tracey, from Derbyshire, who said: 'They never made it. I phoned and could here shouts in the background and knew instantly something was wrong. I'm in shock."

Video: Forensics officers search scene of Pc's murder

Around 10 people in blue overalls, apparently forensics officers, were seen on their hands and knees, searching the cobblestones in a horizontal line in New Palace Yard, near where Pc Palmer was stabbed and the attacker was shot.

An area of the courtyard remained cordoned off and a blue tent was in the spot where Pc Palmer fell.

Queen sends 'thoughts, prayers, and deepest sympathy'

The Queen has said her "thoughts, prayers, and deepest sympathy" are with all those who have been affected by yesterday's "awful violence". She wrote in a message to Acting Commissioner of the Met Craig Mackey:

"Following the shocking events in Westminster, Prince Philip and I are sorry that we will not be able to open the New Scotland Yard building as planned today, for very understandable reasons. I look forward to visiting at a later date.

"My thoughts, prayers, and deepest sympathy are with all those who have been affected by yesterday's awful violence.

"I know I speak for everyone in expressing my enduring thanks and admiration for the members of the Metropolitan Police Service and all who work so selflessly to help and protect others."

Pope sends message assuring the 'nation of his prayers'

Pope Francis has sent a message to Cardinal Vincent Nichols, Archbishop of Westminster, assuring the "nation of his prayers" after yesterday's terror attack.

The message, communicated via the Holy See's Secretary of State, Cardinal Pietro Parolin, commends those who died to the loving mercy of Almighty God as Pope Francis "invokes divine strength and peace upon their grieving families".

Jeremy Corbyn: 'We are united by our humanity and by our democratic values'

Labour leader Jeremy Corbyn also paid tribute to Keith Palmer, the police officer who lost his life in the attack, and to the police and security services who "keep us safe every day" on the Parliamentary estate.

He said: "Today we are united by our humanity and by our democratic values and by that human impulse of solidarity to stand together in times of darkness and adversity.

"I express my condolences to the family and friends of police officer Keith Palmer who gave his life yesterday in defence of the public and of our democracy."

He added: "We especially pay tribute to the bravery of those who took action to stop the perpetrator of yesterday's assault."

More from Theresa May's speech on the victims and the attacker

On the injured

Mrs May said those injured included 12 Britons, three French children, two Romanians, four South Koreans, two Greeks, and one each from Germany, Poland, Ireland, China, Italy and the United States. Three police officers were also hurt, two of them seriously.

Mrs May said the victims also included three police officers who were returning from an event to recognise their bravery.

"Two of those three remain in a serious condition," she added.

On the attacker

Mrs May said the attacker had been identified as someone known by police and MI5, and the working assumption was that he was inspired by Islamist terrorism.

She said it was still believed that the attacker acted alone and there was "no reason to believe" further attacks on the public were planned. She added:

"His identity is known to the police and MI5 and when operational considerations allow, he will be publicly identified.

"What I can confirm is that the man was British-born and that some years ago he was once investigated by MI5 in relation to concerns about violent extremism.

"He was a peripheral figure. The case is historic. He was not part of the current intelligence picture.

"There was no prior intelligence of his intent or of the plot."

'Our values will prevail'

Mrs May concluded her statement by saying: "Our values will prevail."

Mrs May said it was an attack on free people all over the world as she thanked global allies including US President Donald Trump for their support. The PM said:

"We meet here in the oldest of all parliaments because we know that democracy and the values it entails will always prevail.

"Those values - free speech, liberty, human rights, and the rule of law - are embodied here in this place but they are shared by free people around the world.

"A terrorist came to the place where people of all nationalities and cultures gather to celebrate what it means to be free. And he took out his rage indiscriminately against innocent men, women and children.

"This was an attack on free people everywhere, and on behalf of the British people I would like to thank our friends and allies around the world who have made it clear that they stand with us at this time."

Praise for police for 'heroically' doing their job

Mrs May praised the police for "heroically" doing their job by stopping the attacker getting access to Parliament. She said:

"We should be clear first of all that an attacker attempted to break into Parliament and was shot dead within 20 yards of the gate.

"If his intention was to gain access to this building, we should be clear that he did not succeed. "The police heroically did their job."

MI5 is 'fully mobilised in support of the police', says chief in rare public statement

Director General of MI5 Andrew Parker has condemned the Westminster attack as "appalling and disgusting" and said the agency's operational response is "fully mobilised in support of the police". He said in a statement:

"The thoughts of the men and women of MI5 are with the families of those killed in Westminster yesterday, and with the other innocent people injured in this appalling and disgusting attack.

"We stand shoulder to shoulder with our police colleagues, grieving at their loss while also applauding the professional excellence of their response.

"As Acting Deputy Commissioner (Mark) Rowley said, the security community prepares for such awful events - while working tirelessly to prevent them.

"The MI5 operational response is fully mobilised in support of the police."

Pictures from sombre Westminster as MPs return to 'business as usual'

A sombre calm hung over Westminster the morning after the attack. There were none of the large groups of tourists usually seen taking photos outside Big Ben.

Instead the whole area was cordoned off as MPs and staff working in Parliament flashed their passes and filed quietly into an entrance at the side of the building.

The police presence is heavy with dozens of officers, many armed with guns, keeping guard at the entrance.

Forensics investigators and police officers work at the site near Westminster Bridge Credit: NEIL HALL/Reuters

But despite the shock of the terror attack, MPs were determined it will be business as usual in Parliament.

SNP MP Alan Brown (Kilmarnock and Loudoun) said: "I feel a slight sense of apprehension, but we can't let the crimes of one person prevent the working of Parliament.

"Obviously, our thoughts are with the family of the policeman and other people who were killed.

"I suspect it will be an emotional day, it will certainly be a very sombre day, in Parliament. Today it is back to business.

"I've got a question on the order paper and a constituency matter to raise, so it is back to the day job of being an MP."

Police cordon in Westminster the day after the terror attackCredit: Geoff Pugh for the Telegraph

Barry Gardiner, the shadow international trade secretary, said: "Everything has to be seen to get back to normal as quickly as possible so that people realise that this sort of attack is ultimately a futile gesture.

"I think the police have been absolutely right not to release details of the attacker, to give it no publicity.

"What happened yesterday was sordid, shameful and vile. The attacker caused the most appalling carnage in the lives of 20 to 25 families.

"I think everyone in Parliament will want to pay tribute to the security services and the police and how they responded yesterday, and the officer who tragically died."

Minute's silence was chosen for 9.33am to honour murdered Pc's 933 shoulder number

A minute's silence was held nationwide at 9.33am, including in the Palace of Westminster and at New Scotland Yard, to commemorate the three innocent people killed in Wednesday's assault on Westminster.

The time for the silence was chosen in honour of murdered police officer Keith Palmer's shoulder number - 933.

'They were all dressed in black and armed with machine guns' : The moment police stormed Birmingham flat linked to terror attack

Neighbours have described the dramatic moment armed police stormed a Birmingham flat linked to the Westminster terror attack.

Stunned residents watched as more than a dozen black-clad officers equipped with machine guns smashed their way in to an address in Hagley Road at about 11pm on Wednesday.

The Metropolitan Police have confirmed the overnight raid was part of a wider operation in which several addresses were searched and seven arrests made.

One witness, who works in a shop near the second-floor flat, said: "The man from London lived here." He added: "They came and arrested three men."

A police cordon in Hagley Road, BirminghamCredit: Caters

Stuart Bailey, who lives four doors down, was going for a drink with his friend when an armed officer shouted for him to "Go left".

The 25-year-old said: "There were a load of armed police in the street and on the pavement and I could see three or four in front of me.

"They were all dressed in black and armed with what looked like MP5s (submachine guns) and one of them had six ammunition magazines strapped to his leg.

"I wasn't allowed back in my property for an hour."

Officers enter the flat where the suspect is believed to have livedCredit: Caters

The road was sealed off by balaclava-wearing officers for several hours as the raid continued, although the busy main road into the city has since reopened.

Another man who have lived in the neighbouring flats said he was "scared and frightened" when he glanced out of the window and saw about a dozen armed police wearing Kevlar helmets and body armour in the street.

One man, asked if he knew anything about the men in the flat, recalled two men living there.

He heard one man in the flat speaking on the phone in what he described as an "Arabic or Pakistani accent", saying he had heard it "for the last two or three nights".

Hagley Road was cordoned off for several hoursCredit: Caters

Describing the raid, he said: "There were armed police and some important-looking guys in suits as well.

"They had tools and they were trying to break the doors down, trying to force themselves in.

"We were basically staying in our house, we didn't know what was happening. Even today still we don't know what has happened.

"Somebody said it was to do with the attack on Parliament, and now we're very scared and frightened."

On Thursday morning there was still police activity at the flat, with one of its windows covered with cardboard.

Lord Carlile: 'It is very rare for lone wolves to have no connections'

Lord Carlile, the former independent government reviewer of terrorism legislation, told BBC Radio 4: "This is the sort of attack that we feared, the sort of attack that was predicted by the authorities.

"There may have to be changes in the way that Parliament and other major public buildings are guarded. We have to study what occurred and lean the lessons. It is very rare for so called lone wolves to have no connections whatsoever.

"However, I suspect that when we see the background of this perpetrator we will probably see that he was inspired by something external and we have to address the causes that drive people to commit these terrible crimes."

Security review to investigate if Palace of Westminster police should be armed

Security arrangements at Westminster are to be reviewed following Wednesday's horrific attack. Defence Secretary Sir Michael Fallon said the review would look at whether current security arrangements are "adequate" and whether police at the front gates should be armed.

But he said it was neither possible nor desirable to seal Parliament off from the public.

Police outside the Palace of Westminster shortly after the attackCredit: Victoria Jones/PA

Recap: What we know so far about the Westminster attack

If you're just joining us this morning, here's a quick recap of what we know so far about the Westminster attack. You can read a fuller version here.

Four people have died - a police officer, the attacker, a woman in her mid 40s and a man in his mid 50s

The officer was Pc Keith Palmer, a 48-year-old husband and father with 15 years of police service

Seven people have been arrested and six addresses raided across London, Birmingham and elsewhere

The woman was killed on Westminster Bridge as a number of pedestrians were mowed down by a grey Hyundai

It is believed the man was also killed in the incident on the bridge

Seven people are in a critical condition, and 29 have been treated in hospital

One woman ended up in the Thames and was treated for serious injuries after being pulled from the water

The attacker, armed with two large knives, jumped out of the car after smashing it into the railings encircling the Palace of Westminster, fatally stabbing Pc Palmer as he entered the grounds. He was shot dead moments later by another officer

Defence Secretary Michael Fallon has said the working assumption is that the attack is linked to Islamic terrorism

Parliament and Whitehall to hold minute's silence

MPs, peers and staff working in Parliament and Whitehall will observe a minute's silence at 9.33am to pay respects to the victims of the terror attack.

A large area around the Palace of Westminster, including Parliament Square and Westminster Bridge, remained cordoned off on Thursday morning, but staff were able to access the building and return to work.

The House of Commons will sit after prayers at 9.30am, with the minute's silence expected to follow, and then questions to Liam Fox and ministers from his Department for International Trade.

Two people in overalls and masks were seen sorting through material near the area in New Palace Yard where the attacker was shot and Pc Keith Palmer stabbed, and an area in the courtyard remained cordoned off.

The popular Terrace cafeteria was open and serving a hot breakfast as normal as MPs, peers and staff arrived for work.

The Union flag was flying at half-mast over the Houses of Parliament and other nearby buildings.

Flag at half mast in Westminster on Thursday morningCredit: Eddie Mulholland for The Telegraph

Forensics officers remain in Westminster this morning

Investigators 'looking at who might have helped' attacker

Sir Michael Fallon, the Defence Secretary said investigators were working around the clock.

He said: "They have been working right through the night, looking into his background, how he got hold of the vehicle, where the vehicle has been in the last day or two, and who may, or may not, have helped him."

Asked if he was known to police, Sir Michael said: "I can't confirm that, you will have to ask the police that."

Full statement from Mark Rowley, senior anti-terror officer

Here is the full statement on the Westminster terror attack made by Mark Rowley just now:

"Good morning - I am here to update you on our ongoing counter-terrorism operation following the horrific attack in Westminster.

"Greater clarity is now developing regarding the casualty figures as we have now collated information from the public and five hospitals - the latest figures I have are that there are currently four dead and 29 people were treated in hospital.

"We are still collating numbers of walking wounded and of those in hospital sadly seven of them are in a critical condition.

"Tragically the deaths included Pc Keith Palmer who was protecting Parliament, and two members of the public - a woman aged in her mid 40s and a man aged in his mid 50s.

"The fourth man of course was the terrorist who was shot dead by armed police at the scene.

"Hundreds of detectives have been working through the night and during that time I can confirm we have searched six addresses - and made seven arrests. The inquiries in Birmingham, London and other parts of the country continue.

"It is still our belief - which continues to be born out by our investigation - that this attacker acted alone yesterday and was inspired by international terrorism.

"To be explicit - at this stage, we have no specific information about further threats to the public.

"Clearly our investigation is ongoing - developing all the time - and is focused on his motivation, his preparation and associates.

"I do recognise that the media are making progress in identifying the attacker - I would continue to ask that his name is not published whilst we are at such a sensitive stage in our investigation - and as I state still conducting arrests and searches.

"The large and complicated crime scene remains in place and our work there continues - I would like to thank everyone for their support and patience as we finish this work.

"As people are out and about on the streets of the Capital this morning they will see more police officers on duty - armed and unarmed - and a mix of British Transport Police and the City of London.

"We have cancelled some leave and increased some duty hours and are working to make sure that we can out in force to reassure the public.

"We must not allow terrorists to create discord, distrust and fear.

"The police stand with all communities - later today a meeting of faith leaders will be held here at New Scotland Yard.

"Whilst our work to investigate and understand what happened yesterday continues with vigour - we must also reflect.

"I want to thank the public for their support and all their good wishes - I know it is appreciated by all those men and women who are out there today protecting us.

"Finally, I would also like to ask the public for their continued help and continued vigilance and if you see anything that causes you concern or raises your suspicions do not hesitate to call us - 0800 789 321 - or in an emergency 999. Thank you."

Video: Attacker killed three; 29 treated in hospital

Latest summary from overnight

Armed police have carried out an overnight raid on a Birmingham property, which was reportedly linked to the attack in Westminster on Wednesday.

Counter-terror detectives are continuing to search for clues about about how an armed attacker, believed to have "inspired by international terrorism", brought death and destruction to the streets of London.

Five people were killed in the "sick and depraved" terror attack, including a police officer who was stabbed and his assailant, while dozens more were injured.

Armed police launched a late-night raid on a second-floor flat above a row of shops on Hagley Road in Birmingham. Witnesses have said three people were taken away by police.

Sky News cited unnamed sources as saying the action was linked to the attack in London.

BBC Newsnight had earlier reported there was a suggestion the car used in the attack was hired from an address in Birmingham. However, this has not been confirmed.

Mark Rowley, Scotland Yard's top anti-terror officer, confirmed that 40 people were injured after the attacker - armed with two large knives - mowed down pedestrians with his car on Westminster Bridge then rushed at the gates in front of the Houses of Parliament, stabbing a plain-clothes policeman before he was shot by armed officers.

Keith PalmerCredit: Metropolitan Police

The officer who died was named as Keith Palmer, 48, a husband and father, whose bravery was hailed by colleagues, friends and the many MPs whom he was charged with protecting.

The three other fatalities are understood to be people who were hit by the car on Westminster Bridge.

Mr Rowley declined to name the attacker, but said police suspect he was "inspired by international terrorism" - and that they believed they knew who he was.

Witnesses described scenes of terror when gunfire rang out as the attacker approached a second officer within yards of the Houses of Parliament.

The suspected attacker was pictured being treated by paramedics on a stretcher, as two knives used in the assault lay on the ground nearby.

Paramedics fought to save his life and that of Mr Palmer on the floor of the cobbled courtyard in front of Parliament, with Foreign Office minister Tobias Ellwood among those who rushed to help.

"Heartbroken" former colleague, Conservative MP James Cleverly, paid tribute to the "lovely man" he had known for a quarter of a century.

"I've known Keith for 25 years. We served together in the Royal Artillery before he became a copper. A lovely man, a friend. I'm heartbroken.

"My thoughts are with the family, friends and colleagues of Pc Keith Palmer. A brave man."

The suspected London terror attacker being treated by paramedics, with the knives used in the assault circledCredit: Stefan Rousseau/PA

The killer managed to get in through a vehicle gate in New Palace Yard – used by the Prime Minister and other members of the Government – because it was not locked.

Prime Minister Theresa May has described the attack as "sick and depraved".

Speaking outside 10 Downing Street after chairing a meeting of the Government's Cobra emergencies committee, Mrs May paid tribute to the "exceptional men and women" of the police force who responded to the attack.

Mrs May said that any attempt to defeat the values that Parliament stands for was "doomed to failure".

And she vowed: "We will all move forward together, never giving in to terror and never allowing the voices of hate and evil to drive us apart."

Footage later emerged of the moment police opened fire after the attacker drove a grey Hyundai i40 across Westminster Bridge before crashing it into railings then running through the gates of the Palace of Westminster.

In other developments, another woman who apparently fell into the Thames was rescued and given urgent medical treatment on a nearby pier.

London Ambulance Service said paramedics had treated at least 10 patients on Westminster Bridge. A party of French schoolchildren were among those targeted on the bridge, with three injured.

Mrs May, who was ushered away from Parliament after the attack, was chairing a meeting of the Government's emergency Cobra committee.

The attack left a trail of destruction as paramedics tended to victims on the bridge and at the gate.